2.1. SWEET CORN
Maize (Zea mays) or corn has long been one of the most important food crops in the Western hemisphere being grown for both human and animal consumption. Because of the importance of the crop, corn breeders have focused a great deal of attention on improvement of a number of generally valuable characteristics, such as yield, tolerance of environmental stress, and disease and insect resistance. In specific connection with human consumption, particular efforts have been devoted to the development of a product with an improved taste, especially with respect to increasing the sweetness of the kernels. The most active area of research has been centered around manipulation of the endosperm genes which, to a large extent, control the level of sugar found in the kernel. Of particular interest is the "sugary" allele (su), a recessive mutation of the Su locus on chromosome 4. Sweet corn, by present definition, is homozygous for the recessive allele at this locus. This mutation is associated with the production of large amounts of water soluble polysaccharide (WSP), increased sugars, and greatly reduced amounts of starch, in comparison with field corn varieties. Both the WSP and sugar content significantly contribute to the consumer's perception of the desirable "sweet corn" taste, and both are also important in providing a product which is suitable for industrial processing, e.g., canning and freezing.